Every time I start Sonar and try to use Melodyne, I'm asked to activate it. I click the button, log in, and activate. It tells me that Melodyne 4 is now activated for this computer. The next time I use Sonar the same thing happens. Away from Sonar, I've gone to Celemony's site to check my account, and it says Melodyne 4 "first registration" 24.01.2016, whatever that means.
 
Adding to the annoyance is the fact that I always disable my network adapter before using Sonar, so I need to go back online to get started.
 
What am I doing wrong?

When you installed Melodyne did you run the installer as administrator? If not and you want to try it reinstall it with that addition.  

I had this happen when I originally upgraded.
 
It turned out that I had downloaded the initial version which was exhibiting the same symptoms you are seeing.  I updated to the newest version (at that time), performed an uninstall of the initial version, and an install of the newest version and it behaved as expected.
 
I'm currently using version 4.0.4.001 at this time, which is the most current version.
 
Hope this helps,
Paul

That fixed it. Thanks.

Actually, it only works if I'm connected to the internet. If I'm offline, it still asks me to activate.  i'll probably need to ask Celemony about it.